211255576661 has 2 divisors, whose sum is σ = 211255576662. Its totient is φ = 211255576660.

The previous prime is 211255576643. The next prime is 211255576691. The reversal of 211255576661 is 166675552112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106647964900 + 104607611761 = 326570^2 + 323431^2 .

It is a cyclic number.

It is not a de Polignac number, because 211255576661 - 2¹⁴ = 211255560277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211255576691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105627788330 + 105627788331.

It is an arithmetic number, because the mean of its divisors is an integer number (105627788331).

Almost surely, 2^211255576661 is an apocalyptic number.

It is an amenable number.

211255576661 is a deficient number, since it is larger than the sum of its proper divisors (1).

211255576661 is an equidigital number, since it uses as much as digits as its factorization.

211255576661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756000, while the sum is 47.

The spelling of 211255576661 in words is "two hundred eleven billion, two hundred fifty-five million, five hundred seventy-six thousand, six hundred sixty-one".